1. Field of the Invention
The invention relates to a brake control device and a brake control method that control the braking force applied to wheels provided in the vehicle.
2. Description of the Related Art
Japanese Patent Application Publication No. 2006-123889 (JP-A-2006-123889) describes a hydraulic brake device that includes a hydraulic pressure booster, a master cylinder, a power hydraulic pressure source, and a plurality of brake cylinders. According to this hydraulic brake device, the brake cylinders are selectively connected in communication with the hydraulic pressure booster, the master cylinder and the power hydraulic pressure source through the use of a simple circuit, so that the controllability can be improved. When the system is normal, the working liquid is supplied from the power hydraulic pressure source to the brake cylinders. If an abnormality is detected, the control mode is switched to a control mode that is different from the control mode selected during the normal state. At the time of switching the control mode, a plurality of control valves provided within the brake device are altered in the open/closed state.
It is considered to be desirable that the switching of the control mode as mentioned above be promptly performed. Therefore, the open/closed state of the control valves provided within the brake control device will be altered basically simultaneously. However, depending on the situation immediately prior to the mode switching, there is possibility that hydraulic pressure may be confined in a wheel cylinder due to the switching operation. If the confinement of wheel cylinder pressure occurs, a corresponding one of the wheels is caused to have a drag.